soundwire: stream: add missing const to Documentation

Commit 21f4c443 ("soundwire: stream: constify sdw_port_config when
adding devices") added const to sdw_port_config argument, but forgot
documentation.

Fixes: 21f4c443 ("soundwire: stream: constify sdw_port_config when adding devices")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240117160639.1327266-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/driver-api/soundwire/stream.rst

@@ -324,12 +324,12 @@ framework, this stream state is linked to .hw_params() operation.
 
   int sdw_stream_add_master(struct sdw_bus * bus,
 		struct sdw_stream_config * stream_config,
-		struct sdw_ports_config * ports_config,
+		const struct sdw_ports_config * ports_config,
 		struct sdw_stream_runtime * stream);
 
   int sdw_stream_add_slave(struct sdw_slave * slave,
 		struct sdw_stream_config * stream_config,
-		struct sdw_ports_config * ports_config,
+		const struct sdw_ports_config * ports_config,
 		struct sdw_stream_runtime * stream);